Better Brain-Computer Interfaces with Ultrasound Transducers

BY BLORGE /September 26, 2011 11:31 am

According to engineers in Canada, ultrasound can be used not only to monitor fetuses and identifying heart defects but it can help tell what people are thinking. As IEEE.org reported recently, a new research suggests that ultrasound-based devices could lead to a new kind of brain-computer interface.

Biomedical engineer Tom Chau and his colleagues at the University of Toronto reveal that ultrasound can also monitor brain activity, suggesting that it could be used for brain-computer interfaces.

The researchers used lightweight ultrasound headgear to measure blood flow in the brains of nine adults as they alternated between relaxing and performing two mental tasks. One task required them to think of words that began with a letter displayed on a video screen, and the other asked them to compare two objects rotated to different angles and determine whether they were the same object or mirror images of each other.

Using this new technique, researchers could see with 82.9 percent accuracy whether people were performing the word-generation task and they could tell with 85.7 percent accuracy if they were doing the mental-rotation tasks or just relaxing.

Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from “normal” (audible) sound based on differences in physical properties, only the fact that humans cannot hear it. The production of ultrasound is used in many different fields, typically to penetrate a medium and measure the reflection signature or supply focused energy. Source: Wikipedia